Protypusia xizangensis Gibbs 2023, gen. et comb. nov.

Protypusia xizangensis (Yang & Yang, 1994) gen. et comb. nov.

Usia xizangensis Yang & Yang, 1994: 272.

Etymology

Named after the type locality Xiang, Langkazi in Tibet.

Type material (not examined)

Holotype (specimen not seen but photographs of holotype examined)

CHINA • ♀; “Xizang [Tibet], Langkazi (4300 m), 30 August 1978, [Leg.] Fasheng Li”; CAU.

Other material examined

None.

Redescription

Male

Unknown.

Female (based upon the type description and photographs of holotype)

MEASUREMENTS. Body length: 3.0 mm. Wing length: 3.5 mm.

HEAD. Dark in ground colour, obscured by grey dust. Gena plus mouth margin relatively broad, in part yellowish in ground colour, a little less than width of proboscis, the dusted gena narrower than the more shining mouth margin. Frons a little less than a third of head width, widening out towards front, densely grey dusted, small central dark spot. Occiput as frons well furnished with yellow hairs. Ocellar triangle equilateral, lateral ocelli well separated from eyes by more than twice diameter of these ocelli. Antenna black (postpedicel missing). Proboscis black, moderately long a little longer than thorax including scutellum, or twice head length, palps black.

THORAX. Blackish ground colour, densely covered with grey-brown dust. Mesonotum with blurry brown paramedian vittae and obscure darker antehumeral vittae broken at transverse suture. Scutellum similarly dusted, or a little greyer. Mesonotum and scutellum with yellow hairs. Pleura densely dusted, greyer then on mesonotum

WING. Hyaline, veins dark brown to black, yellower towards base, and subcosta entirely yellow. Crossvein r-m in basal third of discal cell, just a little beyond m-cu.

HALTERE. Yellow, except brownish base of stem, and a clear brown spot on dorsum of knob.

LEGS. Black with abruptly yellow apices to all femora and narrowly at base of all tibia. Coxae and femora covered with grey dust, as are tibia and tarsi [more thinly so?], all with short yellow hairs.

ABDOMEN. Black covered with olive-grey dust, denser laterally, disc of basal tergites subshining as if thinly dusted. All tergites with clear yellow apical margins approximately a quarter the length of respective tergites, narrowing on reflexed lateral margins. Yellow hairs on tergites and sternites.

Remarks

Based on available keys, Yang & Yang (1994) compared this species with U. aenea (Rossi), a quite different species with shining, strongly sclerotised cuticle lacking yellow on legs and abdomen. Within Usia s. str. it is superficially much closer to U. transcaspica of central Asia, which has yellow on legs and apices of tergites, but like U. aenea, this species also has the tergites and disc of mesonotum shining, undusted. Yang & Yang’s Usia xizangensis clearly belongs in Protypusia gen. nov. and not Usia based on the heavily dusted mesonotum and abdomen and the tergites not strongly sclerotised so not holding their shape on drying. Based on what can be seen in the available photographs, it seems to be closest to Pro. negevi, but this species has a longer proboscis, clear white knob of haltere and generally pale blue-grey dusting. None of these characters, either individually or together, absolutely eliminate the possibility that these taxa are conspecific, similar variation can be seen across populations of other species of Usiini. However, it would be remarkable if the distribution of Pro. negevi stretched all the way from the Negev Desert to the high plateau of Tibet, far more likely that Pro. xizangensis is a distinct species.

Distribution

China (Tibet).